 
 
 
10.3.5  Collecting logarithms
The lncollect
command collects the logarithm in an expression; namely, it rewrites
sums of logarithms as the logarithm of a product.
- 
lncollect takes
expr, an expression.
- lncollect(expr) returns
expr with the logarithms collected.
It may be a good idea to factor the expression with factor
before collecting by lncollect).
Examples
| lncollect(ln(x+1)+ln(x-1)) | 
|  | | | ln | ⎛ ⎝
 | ⎛ ⎝
 | x+1 | ⎞ ⎠
 | ⎛ ⎝
 | x−1 | ⎞ ⎠
 | ⎞ ⎠
 | 
 |  |  |  |  |  |  |  |  |  |  | 
 | 
| lncollect(exp(ln(x+1)+ln(x-1))) | 
Remark.
Note that, for Xcas, log is the natural logarithm, the same as
ln; for the base 10 logarithm, use log10.
 
 
